Hydraulic Lifters Bleed Down Time

[petryshyn]

Re: Hydraulic Lifters Bleed Down Time

I can understand 3.5psi as a fuel pressure although I would rather see 5-7psi. I've seen then down as low as 2.5, but 1.5psi sounds low, even if its on your good engine. I question your gauge, and where you are tapping into the system. Is there a fuel bypass return on the system?<br />As clanton asks, what is the compression? Again, all the variables can be identified by comparing the vacuum from one engine to another. We need numbers and consistancy. <br />>Did you "power time" the engine or use a timing light? A dampner pulley (harmonic balancer) can slip and skew your timing marks. Either establish piston TDC manually and check the marks, or power-time the engine(preferred).<br /><br />What is a dizy?

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

dizy is aus slang for distributor<br />understand u need numbers will be on boat tomorrow and will confirm<br />presure was at inlet to carb<br />again all good comments,thanks<br />the cam timing sounds a lot like the symptons as dose the waterflow, most difference in sound is under power.<br />thanks again will get numbers

 

[petryshyn]

Re: Hydraulic Lifters Bleed Down Time

I would also recommend you power time the engine. That means advance the timing to achieve highest RPM while under maximum load with wide open throttle......

 

[DJ]

Re: Hydraulic Lifters Bleed Down Time

The vacuum readings will verify this, however a timing chain that has skipped a tooth will make for a sick engine. It will run, but the power will be way off.

 

[DJ]

Re: Hydraulic Lifters Bleed Down Time

The vacuum readings will verify this, however a timing chain that has skipped a tooth will make for a sick engine. It will run, but the power will be way off.

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

hi guys<br /><br />did some more today<br /><br />here are the results<br /><br />swapped distributors and redid timing - no difference<br /><br />took vac readings both motor at idle 21-22 <br />vac readings 2500 rpm 24-25<br />however<br />under load at 1800 rpm good motor 18<br />under load at 1800 rpm bad motor 13<br />more load on bad motor caused a further decrease and stayed low around 10<br />good motor stayed around 18 with further load<br />needle steady on both<br />It seems as if the bad motor looses its vacume as the load increases, so probably get's to 3000rpm with not enough vac to go further.<br />This is diffinite and different from the good motor, which tends to hold its vacume.<br />I was not in a position to check at WOT but this is the first diffinite indication.<br /><br />Not sure waht this means, but sounds like valve timing. Compression test is fine with all within 5lb of 150, so do suspect valve / rings.<br /><br />I would appreciate your thoughts, my next move will be to check valve timing.

 

[GarageGuy42]

Re: Hydraulic Lifters Bleed Down Time

I know from my experience that if an engine jumps time it generally won't run as good as you describe consistently without belching through the carb. Starting an out of time engine will cause the same symptoms. You can check the slack in the chain by rocking the crank back and forth while looking at the timing marks and get a general idea how loose it is. Approx 20 deg. is pretty loose. Leave the dist cap off while doing the rocking of the crank to know when to strart and stop the rocking by the movement of the rotor. <br />Other than that it sounds like a fuel issue. You could possibly have crud in the jets or have water in the carb bowl. Water will ball up in the fuel and will lay over the jets and won't let fuel through. You would think it would pullit on through but it won't always. You could rev it manually to about 3000 and slam the choke closed till it almost dies and let off the choke and do this a few times. If there is anything plugging the jets it will pull it through.<br />I hope this was some help. If not I tried.<br />I personally love Quadrajets. I think I am one Of few.

 

[Trent]

Re: Hydraulic Lifters Bleed Down Time

What are the compression readings?

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

swapped carbs between motors, changed fuel sources tried most obvious things. pressures ok will find paper with readings but were like 155 160 160 160 150 145 160 155<br />pluggs look even, exhaust seems louder all points to valve train but since compression ok probably valve timimg<br />see other post 318 not getting full revs<br />thanks

 

[clanton]

Re: Hydraulic Lifters Bleed Down Time

A steady low vacuum under load could be clogged exhaust system.<br />Is this the cause of the difference in sound of exhaust?

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

will hold revs off load fine, dont think its exhaust, problem only apparent on load and from about 15oo rpm on vac guage

 

[petryshyn]

Re: Hydraulic Lifters Bleed Down Time

Have you power-timed the engine?<br />Have you partially closed the choke valve while under load to see any RPM change? (checking for lean mixture)<br />Have you done a fuel flow test?<br />Does the engine have a EGR valve?<br /><br />*since your vacuum readings increased slightly from idle to 2500rpm, I don't suspect plugged exhaust or valve timing.<br /><br />*what kind of drives are on these engines. Some loss of HP may be normal on a reverse rotation drive.

 

[clanton]

Re: Hydraulic Lifters Bleed Down Time

The bad engine had 13 inches vacuum at 1800 loaded, more rpms dropped to 10 inches.

 

[Beernutz]

Re: Hydraulic Lifters Bleed Down Time

It's unlikely that all of the lifters would fail at the same time. What's the bleed-down time on the good engine?<br /><br />The 318 Chrysler is one tough engine that'll take a lot of abuse. Don't think I've ever heard of one jumping a tooth on the timing gear. That's a common small block Ford problem with the aluminum cam gear and plastic teeth. 'Course that doesn't mean it doesn't happen to other engines with a ton of hours on them. <br /><br />With your symptoms, I'd put my money on an exhaust restriction.

 

[Beernutz]

Re: Hydraulic Lifters Bleed Down Time

Oh, yeah, one more thing. If she jumped a tooth on the timing gear, you'd have experienced an immediate and drastic change in ignition timing. If that didn't happen, you can forget that possibility.

 

[petryshyn]

Re: Hydraulic Lifters Bleed Down Time

Are both props the same diameter and pitch? Are they both in the same shape?

 

[GarageGuy42]

Re: Hydraulic Lifters Bleed Down Time

Was this a problem that started all at once or was it a gradual problem? What was or has changed since the problem started? I have seen Mopar 318 stock (HD as with a marine engine) that had double row timing chains, I really don't think that is the problem.<br />If the exhaust is restricted, What can get in there to do it? How much ignition advance can you get from a marine engine without ping since it is under the same consistent load unlike an automobile with gear changes?

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

hi guys<br />please see the other post 318 "not getting full revs as well"<br /><br />Summary<br />bought 2nd hand<br />total mess<br />previous owner had no idea and may have changed timing on cam, he did have the ign leads wrong and other things as well, I have spent many hours getting things back in order. Starters, distributors, electronics, wiring, carbs, pcv, fuel pumps, leads, plugs, etc etc all either replaced or rebuilt.<br /><br />Carbs, distrubutors and electronics have been swapped between motors with no change. props have been off and scanned and are within 1/4" of each other. Safts felts free and easy and tend to rotate a little at idle, paragon v drives, tends to indicate its not there. Agree motors rarely are the same but this is a major differene. If it was loosing this power in g/box i think it would be smokin. <br /><br />So<br />not carb not distributor, dont suspect running gear, have change fuel supply from tank to tank.<br />thinking about blocked exhanust but cant see how all have been off and back on and this should show under no load as well especialy with this much power loss. Agree would be strange if all lifters went at the same time. Havn't power tuned it has no egr, if it is advance too much there is trouble starting as you would expect, running about 10dg adv at idle book says 5, seems to like 10 as does other motor.<br /><br />If the fuel supply was running low id expect some missing or something? remember carbs have been swapped. Will recheck fuel pump anyway have tried with all filters out of circuit. Not water in bowl as carbs swapped. Good motor still good.<br /><br />distributors swapped, good still good.<br /><br />my guess seems to be now, that the prior owner may have played with the cam timing, as he did not know about counter rotating setup.<br /><br />As funny as it sounds.<br /><br />The vacume reading is the first diffinite problem noted.<br /><br />The documention I have does not refer to on load but rather idle and revs. The problem is only apparent on load, this is diificult to check because its a 45 min run to open speed water and I need two people one to drive etc.<br /><br />My experience with vac in cars is that it will still hold a reasonable vac under constant load.<br /><br />Is this right? comapre to the good motor it seems to be, so what causes the vacume to go lower and lower as load increases from say around 1500rpm, but not off load, if it was fuel I would expect maybe a drop around 3000, rather than an increasing drop in vac acroos the rpm range.<br /><br />Very strange, I am certainly no expert but am a tradesman with mech knowledge and learning many things on this one.<br /><br />Sincere thanks to all.<br /><br />(whew what a saga) <br /><br />will be interesting to find the fix

 

[petryshyn]

Re: Hydraulic Lifters Bleed Down Time

Hi again<br /><br />>Are you using automotive distributors by chance?<br />>Do the distributors have a vacuum advance?<br /><br />*I highly recommend that you power time the engine. DO NOT TRUST THE TIMING MARKS....

 

[twwmm]

Re: Hydraulic Lifters Bleed Down Time

Thanks schematic<br /><br />not automotive no vac adv, have been swapped between motors. Understand power timing, will try but I feel it is unlikly, whats your opinion on the vacume reading dropping under load almost drops further and further as revs increase?